How do I override or reset a Mac without an admin password?

A while ago, my remote job had mass layoffs and let ex-employees keep our computers. IT claimed they reset the computers remotely, but it didn't seem to work. My issue is that since I don't have access to the admin account, I can't download or update apps. I've been trying to figure out a way to override or factory reset my Mac, but it seems like everything requires I have the admin password. I've tried booting with Cmd+R but nothing happens. Any help is appreciated!